积雪对南极冰盖自动气象站气温观测影响的研究

随着冰盖表面雪的累积或消融,自动气象站(AWS)传感器相对地表的高度随之发生变化,故所记录的观测资料不能直接反映相对地表固定高度上的气象参数。为了使南极冰盖上AWS所获取的气象资料具有可靠性,在积累率对AWS观测气温影响的基础上,将东南极冰盖上中山站至DomeA断面3个AWS的连续观测气温修正到相对于雪表面的某一真实高度上。结果表明:(1)DomeA,Eagle和LGB69年平均1m气温分别为-53.19℃,-41.33℃和-26.29℃,年平均积累率分别为0.11m、0.30m和0.49m,对应的1m气温年平均修正量分别为0.34℃、0.29℃和0.35℃,2m和4m气温的年平均修正量均小于0.1℃;(2)积累率变化对离地表最近层次上的气温影响最大,越往上层影响越小;(3)气温的修正量大小与积累率并非成简单的正比关系,它与气温本身的季节变化特征以及局地近地表逆温强度有很大的关系。气温的平均修正量冬季为正,夏季修正量的正负由局地是否存在逆温决定,修正量值的大小主要由逆温强度和积累率决定。     

误差匹配对自动气象站数据质量的重要性

自动气象站的广泛应用,全面实现了各气象要素的采集、数据处理和资料上传的自动化功能。气象要素的准确性、可靠性和代表性是确保气象产品与服务质量的重要基础,每一个数据与参数的真实可靠都直接关系到气象预报质量和服务效果。由于自动气象站的数据采集器、各个要素的传感器等都有特定的误差,因此,本文拟运用误差匹配朔源方式来减小和消除各环节误差对气象要素和数据质量的影响。     

山西数字地震台网地震自动定位系统运行分析

选取2009年7月至2010年8月山西地震台网速报软件的自动定位结果与＂十五＂Jopens系统人机交互处理的定位结果进行对比分析,得出,速报软件自动定位地震参数与人机交互处理的编目结果基本吻合,可以作为地震速报的依据和参考。     

Automatic reasoning for geometric constraints in 3D city models with uncertain observations

This paper presents a novel approach to automated geometric reasoning for 3D building models. Geometric constraints like orthogonality or parallelity play a prominent role in man-made objects such as buildings. Thus, constraint based modelling, that specifies buildings by their individual components and the constraints between them, is a common approach in 3D city models. Since prototyped building models allow one to incorporate a priori knowledge they support the 3D reconstruction of buildings from point clouds and allow the construction of virtual cities. However, high level building models have a high degree of complexity and consequently are not easily manageable. Interactive tools are needed which facilitate the development of consistent models that, for instance, do not entail internal logical contradictions. Furthermore, there is often an interest in a compact, redundancy-free representation. We propose an approach that uses algebraic methods to prove that a constraint is deducible from a set of premises. While automated reasoning in 2D models is practical, a substantial increase in complexity can be observed in the transition to the three-dimensional space. Apart from that, algebraic theorem provers are restricted to crisp constraints so far. Thus, they are unable to handle quality issues, which are, however, an important aspect of GIS data and models. In this article we present an approach to automatic 3D reasoning which explicitly addresses uncertainty. Hereby, our aim is to support the interactive modelling of 3D city models and the automatic reconstruction of buildings. Geometric constraints are represented by multivariate polynomials whereas algebraic reasoning is based on Wu’s method of pseudodivision and characteristic sets. The reasoning process is further supported by logical inference rules. In order to cope with uncertainty and to address quality issues the reasoner integrates uncertain projective geometry and statistical hypothesis tests. Consequently, it allows one to derive uncertain conclusions from uncertain premises. The quality of such conclusions is quantified in a way which is sound both from a logical and a statistical perspective.     

宁夏气象资料自动归档管理系统设计与实现

气象探测资料种类多、数据量大,早期宁夏实时气象探测资料主要存储在各类服务器中,如何便捷高效地使用气象探测资料是困扰业务人员的难题。本文首先分析了宁夏气象资料归档业务需求,制定了气象资料自动归档策略;其次,介绍了系统的总体架构,阐明了各功能模块的设计思路;再次,采用了MySQL、NAS和Bootstrap等关键技术,设计开发了“宁夏气象资料自动归档管理系统”;最后,统计了宁夏气象资料的自动归档情况和展示了资料查询下载效果。经试运行,该系统可以实时自动归档宁夏气象探测资料和基础预报资料,能够查询下载数值模式产品、雷达数据和天气图等归档资料。     

Multiphysics implementation of advanced soil mechanics models

Using multiphysics computer codes has become a useful tool to solve systems of partial differential equations. However, these codes do not always allow for the free introduction of implicitly defined state functions when automatic differentiation is used to compute the iteration matrix. This makes it considerably more difficult to solve geomechanical problems using non-linear constitutive models. This paper proposes a method for overcoming this difficulty based on multiphysics capabilities. The implementation of the well-known Barcelona basic model is described to illustrate the application of the method. For this purpose, without including formulation details addressed by other authors, the fundamentals of its implementation in a finite element code are described. Examples that demonstrate the scope of the proposed methodology are also presented.     

辽宁数字地震台网地震参数自动处理系统的研制

通过对数字地震观测台网记录的地震．P波和S波震相的振幅、周期、偏振等多种特征进行分析，利用这些特征进行地震震相自动识别，在此基础上进行自动定位。本文主要介绍了地震事件的自动判别、地震震相自动识别、地震的自动定位三个方面的内容。     

全三维地震解释

三维地震为油气工业的增储上产作出了重大贡献，随着采集处理成本的不断降低，周期的不断缩短，全三维处理和叠前深度偏移等技术的推广应用，以及计算机技术的迅速发展，全三维地震解释已成为国内外致力发展的技术。     

雷达强度数据中的阵风锋特征统计和自动识别

利用江苏南京2009-2012年天气雷达数据结合地面自动站风场资料分析江苏沿江地区阵风锋变化特征、阵风锋弧长与移速关系,及其在雷达反射率因子图像中呈现的总体、局部特征,详细分析了三种窄带回波回波带反射率因子分布特征。通过设计反映回波带平坦性的计算方法实现定量分析窄带回波分布异同功能。根据回波带径向波形特征判断径向波形的波宽、波峰个数、波峰阈值和波形双边梯度等特性,实现阵风锋径向波段识别。在对反射率因子图像预处理基础上,结合回波平坦性测试方法和阵风锋径向波形识别算法达到自动识别阵风锋回波的目的。识别效果表明:回波带平均值5 d BZ的独立阵风锋回波识别准确率达87%以上,回波带平均值10 d BZ的混合型阵风锋回波识别准确率达89%以上。对弱阵风锋识别成功率仍较低。     

城镇化发展阶段划分

Northam认为城镇化呈"s"型曲线发展,其过程可划分为三个阶段,这为众多研究证实和引用,但其阶段分界点长期缺乏严格的数学定义.运用高等数学方法,推演出城镇化"s"型曲线的Logistic增长模型关于时间变量t的方程表达式,并通过定性与定量分析,推导出该曲线的三个特征点及其数学表达式.对Northam城镇化发展阶段划分思想进行进一步的讨论,提出城镇化发展"s"型曲线上两个曲率最大点为城镇化三个阶段的分界点;验证了在拐点处城镇化发展速度最大加速度为零,之前速度逐渐加大,之后速度逐渐减小;给出了阶段划分点、拐点和第二阶段历时与平均速度的计算公式.选择日本和其他22个国家城镇化历史数据进行拟合分析,城镇化阶段划分结果与相关研究非常吻合,并且符合世界城镇化发展的总体趋势,还特别证明并指出2004年中国城镇化发展已经出现速度拐点,验证了模型推导的结果.最后讨论了该方法的适用性和局限性.